Solve for $x$ : $3x + 9 = 10x + 2$
Explanation: Subtract $3x$ from both sides: $(3x + 9) - 3x = (10x + 2) - 3x$ $9 = 7x + 2$ Subtract $2$ from both sides: $9 - 2 = (7x + 2) - 2$ $7 = 7x$ Divide both sides by $7$ $\dfrac{7}{7} = \dfrac{7x}{7}$ Simplify. $1 = x$